Humidifier control system

ABSTRACT

Humidifier for hot air heating systems having a waterevaporating pan with an overflow, means to supply water to said pan, at a rate exceeding the rate of evaporation, a removable partially submerged fin, a float chamber receiving the overflow and having an adjustable bleed, and a float actuated switch to control the water supply.

United States Patent Swart, Sr.

[ Feb. 8, 1972 [54] HUMIDIFIER CONTROL SYSTEM [72] Inventor: Richard H.Swart, Sr., 817 Onondaga Ave., Syracuse, NY. 13207 [22] Filed: May 4,1970 [2]] Appl. No.: 34,038

[52] US. Cl. ..l26/ll3, 261/70, 261/D1G. 46 [51] Int. Cl. ..F24f 3/ 14[58] Field ofSearch ..l26/ll3; 261/97,99,70, DIG. 46

[56] References Cited UNITED STATES PATENTS 3,157,716 11/1964 Morris .Q..261/97X 2,708,435 5/1955 Lewis ..126/1 13 3,265,371 8/1966 McGi-ath..l26/l13 X 3,302,631 2/1967 Kellogg ..126/1 13 3,314,412 4/1967 Krause..l26/l 13 3,136,829 6/1964 Skerritt.... .....126/1 13 X 3,188,0616/1965 Alguire .261/DIG 46 3,315,948 4/1967 Martin ..l26/ll3 X PrimaryExaminer-Charles J. Myhre Attorney-Francis P. Keiper [57] ABSTRACTHumidifier for hot air heating systems having a waterevaporating panwith an overflow, means to supply water to said pan, at a rate exceedingthe rate of evaporation, a

removable partially submerged fin, a float chamber receiving theoverflow and having an adjustable bleed, and a float actuated switch tocontrol the water supply.

11 Claims, 5 Drawing Figures INVENTOR. RICHARD H SWART SR.

ATTORNEY HUMIDIFIER CONTROL SYSTEM This invention relates to humidifiersand more particularly to humidifiers for forced hot air-systems andcontrol means therefor.

Humidifiers heretofore employed in hot air ducts generally haveconsisted of water evaporation pans with some form of feed to maintain alevel of water in the pan. As water is evaporated from the pan, thesolids such as lime and other foreign matter in the water is left as adeposit and in a short time the buildup of foreign matter is such as tointerfere with the heat transfer effecting evaporation, as well astending to interfere with the liquid level control.

The present invention is directed to a humidifier wherein the waterlevel is controlled in one or more pans by an over flow bleed whichremoves continuously during water feed, some of the water from the pan,the water so bled containing a substantial portion of the impuritieswhich would otherwise be left to accumulate in the pan.

More particularly the humidifier pan or pans are supplied with water forevaporation at a fixed predetermined rate in excess of the evaporationrate, the excess with impurities concentrated therein being bled off byoverflow, provision being made for a relatively fixed rate of bleed,irrespective of evaporation rate, which bleed rate, when exceededeffects controls of the water supply valve to temporarily suspend feed.

The above and other novel features of the invention will appear morefully hereinafter from the following detailed description when taken inconjunction with the accompanying drawings. It is expressly understoodthat the drawings are employed for purposes of illustration only and arenot designed as a definition of the limits of the invention, referencebeing had for this purpose to the appended claims.

In the drawings, wherein like reference characters indicate like parts:

FIG. 1 is a schematic perspective view of an evaporator disposed in anair duct, with a wall cut away, and indicating water supply and overflowbleed controls;

FIG. 2 is a top plan view of a float actuated bleed control withelectric control circuitry;

FIG. 3 is a sectional view of the control taken substantially on theline 33 of FIG. 2;

FIG. 4 is a fragmentary sectional view of the float chamber of thecontrol taken substantially on the line 3-3 of FIG. 2 with the floatchamber filled; and

FIG. 5 is a sectional view of a modified control employing a mercuryswitch.

Referring to FIG. 1, there is shown a hot air duct in which are locatedlevel waterevaporating pans 22 and 24, one above the other. In each pansinuous fins 26 are arranged with their lower convolutions submerged inthe water in the pan, and the upper convolutions disposed in a mannersuch as to permit the relatively free passage of hot air through theduct, for example in the direction of arrow A, while offeringsubstantial surface for heat transfer from the hot air to the fins fortransfer of heat into the water in the pan to heat the water and promotethe evaporation thereof at a suitable rate.

The upper pan 22 is provided with a water supply line 30 controlled by asolenoid valve 32. The line is also provided with a needle valve 34 tocontrol the flow rate, when the valve 32 is opened. The upper pan isalso provided with a short over flow tube 36 extending through the panbottom, and having a water level controlling annular lip 38. The tube 36is so positioned as to overflow into the pan 22 therebelow.

The water level of the lower pan is controlled by an overflow aperturein a sidewall 40 of the pan, the aperture leading into a conduit orbleed tube 42 leading to a bleed float control 44 disposed at a level inrelation to the water level in the pan 22, such that overflow water mayreadily flow into the float control 44, and rise in the bowl or floatchamber 46 thereof to a level sufficient to actuate the control switch.

The bleed control as shown in FIGS. 2-4 comprises the float chamber 46having a sidewall connection to the end of the bleed tube 42. Thechamber is provided with a circular or cylindrical sump 48 having outletports 50 in the bottom 52.

A stem 54 threaded centrally in the sump bottom, has at its upper end acircular disk or head 56 adapted to be moved up or down in the sump.Disposed in the sump beneath the bead and around the stem is an annularmass of loose fiber glass 58. By raising or lowering the head 56, thefiber glass mass may be compacted to such a degree as to control therate of bleed from the float chamber.

In practice the bleed control may be located over a drain pan 60 havinga drain conduit 62. Within the float chamber, is a ball float 64 adaptedto rest on an annular seat 66 above the sump, when the water level inthe chamber is below a certain level to thereby close off the sump fromthe chamber.

Above the float is a resilient arm 70 mounted to one side of the floatchamber on a bracket 71 and extending over the float, the arm havinginclined centering fingers 72 adapted to engage the ball float when itrises in response to a rise in the water level in the chamber. The armis provided with an upwardly extending projection 74 on its end, adaptedto engage the upperresilient leaf of a pair of normally closed contactmembers 76 and 78 also supported from the bracket 71.

In practice the arm 70 and contact leaves or members 76 and 78 may bedisposed between spaced insulation collars 80 and.82 disposed about aninsulating sleeve 86, on a bolt 88 extending into the bracket 71.

In FIG. 4, the float is shown as having actuated the upper switch leafto open the contacts 90, the arm 70 having limited upward movement byabutment against the underside of the relatively stiff leaf 78.

In FIG. 5 there is shown an alternative switch in utilizing a smallmercury switch 91 mounted on an arm 92 pivoted on a bracket 94 extendingfrom the wall of the chamber 46, the arm extending over the ball 64thereshown. The rocking of the arm may be limited from a position wherecontact in the mercury switch is made when in the position shown in FIG.5, and broken when rocked clockwise by the lift of the ball in responseto an increase in water level in the chamber, to a position where thearm 92 engages an abutment 96, as indicated at 92.

The chamber may have an overflow 98 to prevent water from rising to thelip of the float chamber.

Referring to FIG. 2, there is shown a circuit including the switchcontacts (or mercury switch 91) and water solenoid 100 for the connectedin parallel with a gas valve solenoid 102 to a room thermostat 104, allsupplied from a stepdown transformer 106. When the thermostat I04closes, a circuit will be established through contacts 90 (or mercury)to open the water by energizing solenoid 100 to open water valve 32,provided contacts 90 are closed. When the thermostat I04 closes, valve102 is opened to supply fuel to the hot air furnace and power to theblower. At the same time assuming float switch contacts 90 are closed,water commences to flow into tray 22 and overflows into tray 24, whichin turn overflows into float chamber 46 from which it bleeds through theports 50, as soon as the chamber 46 fills sufficiently to lift the ball64 from its seat 66. If the overflow rate from pan 24 exceeds the bleedrate through ports 50, the float 64 rises, deflecting arm 70, andlifting contact arm 76 to open the contacts 90. When the contacts 90open, the water supply valve is closed, until the chamber 46 bleedssufficiently to permit the contacts 90 to reclose. In this manner thereis provided a relatively constant bleed rate from the chamber 46, whichestablishes the average rate of overflow from the pans, such averagerate being sufficient to eliminate a substantial portion of the solids,in solution or floating, by means of the overflow water being a contheideal relative humidity for a wide range of outdoor conditions. Forexample, with an outdoor temperature of F., with indoor humidities of 25percent, windows, and walls will not receive undue condensation, whereaswith +20 F., a relative humidity of 35 percent is acceptable. As theevaporation of water is in direct ratio to the On time of the furnaceburner, this moisture emission has proven to be the correct amount asrequired for good practice in homes as indicated above.

While a single form of the invention with a modification has beenillustrated and described, it is to be understood that the invention isnot limited thereto. As various changes in the construction andarrangement may be made without departing from the spirit of theinvention, as will be apparent to those skilled in the art, referencewill be had to the appended claims for a definition of the limits of theinvention.

What is claimed is:

1. In a humidifier for hot air heating systems and the like, awater-evaporating pan having an overflow adapted to maintain a fixedlevel of water in the pan, means to supply water to said pan at a rateexceeding the rate of evaporation ro provide continuous flow throughsaid overflow from said pan, and means responsive to a rate of overflowin excess of a predetermined overflow rate for temporarily discontinuingthe supply of water by said water supply means to said pan at the supplyrate exceeding the rate of evaporation, whereby to reduce the overflowrate to the predetermined rate.

2. In a humidifier as set forth in claim I wherein the rate responsivemeans comprises a float responsive switch.

3. In a humidifier as set forth in claim 2 wherein the means to supplythe water comprises a settable bleed valve, and a solenoid flow valve,and in which the solenoid is in circuit with the float responsive switchwhereby a rise in the overflow rate opens the switch and the circuit tosaid solenoid, whereby to cut off the flow through the flow valve.

4. In a humidifier as set forth in claim 1, wherein the pan is providedwith fins, a portion of which are submerged below the level of theoverflow, and the remainder of which are exposed to the stream of hotair of the hot air heating system.

5. In a humidifier as set forth in claim 3, a thermostatic switchconnected in series with a solenoid-actuated fuel supply valve, andhaving the flow valve solenoid and the float switch contacts connectedin series, and parallel with the fuel valve solenoid.

6. In a humidifier as set forth in claim 3, wherein the pan is providedwith removable fins, a portion of which are submerged below the level ofthe overflow, and the remainder of which are exposed to the stream ofhot air of the hot air heating system.

7. In a humidifier as set forth in claim 2, wherein the float responsiveswitch comprises a float chamber having an overflow connection to oneside of the chamber, and a constant flow bleed in the bottom of thechamber.

8. In a humidifier as set forth in claim 7, wherein the constant flowbleed comprises an adjustably compressed annulus of fiber glass disposedabove a bleed aperture in the bottom of the chamber.

9. In a humidifier as set forth in claim 7, wherein the constant flowbleed comprises an adjustably compressed annulus of compressiblepervious material disposed above a bleed aperture in the bottom of thechamber.

10. In a humidifier as set forth in claim 7 wherein the constant flow ofbleed is adjustable.

11. In a humidifier as set forth in claim 7 wherein means are providedfor regulating the rate of bleed.

1. In a humidifier for hot air heating systems and the like, awater-evaporating pan having an overflow adapted to maintain a fixedlevel of water in the pan, means to supply water to said pan at a rateexceeding the rate of evaporation ro provide continuous flow throughsaid overflow from said pan, and means responsive to a rate of overflowin excess of a predetermined overflow rate for temporarily discontinuingthe supply of water by said water supply means to said pan at the supplyrate exceeding the rate of evaporation, whereby to reduce the overflowrate to the predetermined rate.
 2. In a humidifier as set forth in claim1 wherein the rate responsive means comprises a float responsive switch.3. In a humidifier as set forth in claim 2 wherein the means to supplythe water comprises a settable bleed valve, and a solenoid flow valve,and in which the solenoid is in circuit with the float responsive switchwhereby a rise in the overflow rate opens the switch and the circuit tosaid solenoid, whereby to cut off the flow through the flow valve.
 4. Ina humidifier as set forth in claim 1, wherein the pan is provided withfins, a portion of which are submerged below the level of the overflow,and the remainder of which are exposed to the stream of hot air of thehot air heating system.
 5. In a humidifier as set forth in claim 3, athermostatic switch connected in series with a solenoid-actuated fuelsupply valve, and having the flow valve solenoid and the float switchcontacts connected in series, and parallel with the fuel valve solenoid.6. In a humidifier as set forth in claim 3, wherein the pan is providedwith removable fins, a portion of which are submerged below the level ofthe overflow, and the remainder of which are exposed to the stream Ofhot air of the hot air heating system.
 7. In a humidifier as set forthin claim 2, wherein the float responsive switch comprises a floatchamber having an overflow connection to one side of the chamber, and aconstant flow bleed in the bottom of the chamber.
 8. In a humidifier asset forth in claim 7, wherein the constant flow bleed comprises anadjustably compressed annulus of fiber glass disposed above a bleedaperture in the bottom of the chamber.
 9. In a humidifier as set forthin claim 7, wherein the constant flow bleed comprises an adjustablycompressed annulus of compressible pervious material disposed above ableed aperture in the bottom of the chamber.
 10. In a humidifier as setforth in claim 7 wherein the constant flow bleed is adjustable.
 11. In ahumidifier as set forth in claim 7 wherein means are provided forregulating the rate of bleed.